Offhand, I can think of about four different ways to read Hannu Rajaniemi’s rather astonishing debut novel The Quantum Thief, each of them equally valid, each equally inadequate. The first and most obvious is to approach it as Greg Egan-style radical hard SF (or maybe post-radical, since that movement by now is about as middle-aged as its sibling cyberpunk), and Rajaniemi clearly invites such a reading with a storm of barely-contextualized inventions in the first few chapters – a surreal Dilemma Prison run by immortal minds called Archons on behalf of a governing collective called the Sobornost, where prisoners trapped in an infinity of glass cells endlessly battle with millions of copies of themselves; ‘‘warminds’’ with ‘‘non-sequential dorsal streams’’; weaponized Bose-Einstein condensates called q-dots; Oortian spiderships full of virtual butterflies; spimescapes; tzaddiks; exomemories; utility fogs; gevulots; strangelet bombs and nanomissiles – all with scarcely an appositional phrase, let alone an infodump, in sight. It wouldn’t be hard to blame a reader for taking a deep breath a few pages in and concluding that this is going to mean work.

Yet it really isn’t, as it turns out. From another angle, The Quantum Thief is a fairly straightforward cat-and-mouse romantic mystery pitting a master thief against a brilliant boy detective in a world so information-drenched that crime would seem to be impossible. (In a way, this also echoes earlier SF mysteries like Bester’s The Demolished Man, with ubiquitous information technology replacing the rather wobbly notion of psi powers that was so popular in the ’50s). The plot hook is almost pulp: the famous thief Jean le Flambeur is sprung from prison by itinerant spacer Mieli and her wisecracking ship Perhonen, who – after a dizzying setpiece of a quantum space battle with the pursuing Archons – flees with him to Mars for a special assignment commissioned by her mysterious employer. Meanwhile, the boy detective Isidore Beautrelet (he’s described as 15 years old, but Rajaniemi gives us to understand these are Martian years), having just solved the murder of a prominent chocolatier (in a nice touch, chocolate is one of Mars’s main products), learns that his next case will involve le Flambeur. There is, in other words, as much of Maurice Leblanc as of Greg Egan in this mix, and Rajaniemi signals this early on when le Flambeur (the only one of the three main viewpoint characters to get a first-person voice) mentions that Leblanc’s Le Bouchon de Cristal is one of his favorite books, and Isidore Beautrelet himself is borrowed, name and all, directly from Leblanc’s youthful detective in The Hollow Needle, a novel which pits Leblanc’s own Arséne Lupin against Sherlock Holmes, who also gets a shout-out or two later on.

So there are some tissue-traces of Egan here, to be sure, and of Bester, and of Leblanc. But wait, there’s more! There’s a fair bit of reality-testing in the manner of Philip K. Dick, as le Flambeur and others are led to question not only their own identities and memories, but even the universal Martian ‘‘exomemory’’ that provides the community’s consensual reality and history – all of which, in classic paranoid Dickian fashion, may be secretly manipulated by some hidden masters with unknown motives. ‘‘Perhaps the old philosophers were right,’’ muses Isidore’s newest client, ‘‘and we are living in a simulation, playthings of some transhuman gods.’’ For all its intimidating hard science (and you suspect that Rajaniemi, like Egan, knows exactly what he’s talking about), the central new technology in the novel is the very Dickian notion of the gevulot, an elaborate system of information nodes which permits people to control their degree of privacy, while feeding information into the city’s larger ‘‘exomemory.’’ And the Martian colony itself – most of the action is set in a giant moving city called Oubliette, which is involved in a terraforming project – is as politically idealistic as anything in Kim Stanley Robinson. ‘‘We believe in what the Revolution stood for,’’ explains one character. ‘‘A human Mars. A place where we recreate Earth without problems. A place where everyone owns their own minds, a place where we belong to ourselves. And that is not possible when someone behind the curtain is pulling our strings.’’ This political theme, which also echoes the socioeconomic tensions between the inner and outer solar systems that we see in novels like Paul McAuley’s The Quiet War, may be the least developed of the major themes, but comes to play an important role in the backstory which eventually unfolds.

It’s clear that Rajaniemi feels he has to get a lot done with this widely anticipated first novel, and for the most part he succeeds brilliantly. While his opening setpieces – the prison itself and the high-tech space battle between Mieli’s ship and the pursuing Archons – are spectacular enough, Rajaniemi really hits stride with the peripatetic Martian city of Oubliette, where time is literally currency (Isidore’s wealthy client is a ‘‘milliennaire’’), where those whose Watches run out must serve time as Quiets, helping run the city’s infrastructure, and where privacy is a commodity controlled by an elaborate system of protocols and hierarchies enforced by cop-like ‘‘tzaddiks.’’ But Rajaniemi mitigates the alienating effect of his setting by populating his tale with likeable and familiar characters that sometimes approach pop culture archetypes – not only the bandit-roué with a secret past le Flambeur (whose name may also echo a classic Jean-Pierre Melville heist movie), the tough-as-nails adventuress Mieli (so battle-ready she has a fusion reactor embedded in her thigh), and the brilliant young Isidore (whose Holmesian deductions regarding a letter which impossibly appears in his client’s secure home are what finally blows the plot open), but also such comic-book figures as the Gentleman, a phantom rescuer who appears at opportune times throughout the story. Rajaniemi is having as much fun with these characters as with his gonzo physics, and by the end of the novel we’d be willing to follow them down any of the several sequel-corridors that Rajaniemi gives himself. For now, he’s spectacularly delivered on the promise that this is likely the most important debut SF novel we’ll see this year.